US1878793A - Steam injector - Google Patents

Description

Sept. 20, 1932.

R. o. METCALFE ET AL STEAM INJECTOR Filed Jan. 28. 1951 4 Sheets-Sheet l Fig.2

Sept. 20, 1932. MET F ET AL 1,878,793

STEAM INJECTOR Filed Jan. 28, 1951 4Sheets-Sheet 2 By %;s-

. Sept. 20, 1932.

R. D. METCALFE ET AL STEAM INJECTOR Filed Jan. 28, 1931 4 Sheets-Sheet 5 Nvelvfagy I S p 1932- R. D. METCALFE- ET AL 1,373,793

STEAM INJECTOR Filed Jan. 28, 1931 4 Sheets-Sheet 4 3-9-7 a :T-C. 77764122 2 Patented Sept. 20, 1932 RICHARD DAV ID MEICALFE AND STEAM rnarnc'ron f Wane Application filed January 28, 1931, Serial No, 1i1,'834, and in. France November 5,1930.

This invention relates to steam injectors of the type utilizing exhaust or low pressure steam. Such injectors usually havea supply of live steam known as supplementary live steam for thepurpose of increasing the delivery pressure of the injector. They also have a supply of live steam known as auxiliary live steam for working the injector when exhaust or. low, pressure steam is not available due to the fact that the engine from which the injectornormally' derives its ex haust'or low pressure steam is either not working or is not receiving any steam.

The injector has an automatic valve there- "a in which ensures that theauxiliary live steam supply is available immediately the supply of steam to the engine (from which the injectorlderives its exhaust or low pressure steam) is cut oif; The injector also has an automatically operated valvefor'closing the passage through which exhaust or low pressure steam passes into the injector when such steam supply is not available. Such automatic valve is opened by live steam pressure when steam is being supplied to the engine,

and is closed by a supply is cut on. i I In practice it is found that when the steam supply to the engine is restored after it has been cut oif, the'automatic valve which opens to uncover the passage by which exhaust or low pressure steam enters the injector is opened before such exhaust'or low pressure steam reachesthe injector, with the result that any air whichmay be in the pipe line conveyingthe exhaust steam. enters thei'njectorand causes difliculties in re-starting the injector. 1 I 7 One of the objects 'of ourpresent invention spring when such steam is to provide means for preventing the pas sage of air into the injector due to the open- 7 ing of the automatic valve before exhaust or low pressure steam is available at the inj ector. V

Another object of our present invention is low pressuresteam 1s opened, but such JAMES onoxon METcALrE; or ROMILEY, ENGLAND to'provide an improved-valve -for controlling thersupplies of auxiliary and supplementary live steam to the injector. N 1 i f ur invention comprises the provision in thepassage leading between the steam-chest or steam supply connection of the engine from-which exhaust or low pressure steam is derived for, working the injector, of afdelay v'alve'adapted to limit the rate at Whichsteam fromsuch steam'lchest or pipe oan-p'assto the injector for'opening the valve which al-" lows live steam to pass-into the cylinder. of

the piston. w controlling the passage by which exhaust or enters the injector, 'so

valve is not opened for an appreciable period after steam has been admitted to the steam chest or steamflsupply pipe of the'engine, whereby we ensure that that such automatic exhaust or low pressure steam from such engine is available at delay valve allows free flow of steam 111 a reversethrection.

the valve when the latter h opens the automatic valve i Our invention further comprises a control valve for the auxiliary and-supplementary live steam supplies which wh-en operated positively opens the auxiliary live {steam supply connection but only opens thelsupplementary live steam supply connection'after a predetermined amount 'of opening movement of the auxiliary live steam supply valve, and allows a regulation of the quantity of supplementary steam admitted to: the in jectorr i Referring to'tlie accompanying sheets of explanatory drawings i v Figure 1 is a diagrammatic view illustrating an exhaust injectorinstallation with its auxiliary and supplementary live steam convalve before retrol valve and the delay ferred to.

Figure 2 is a sectional elevation drawn' to' V a larger scale of the delay valve.

, Figure 3 is a sectional elevation'inidiagrammatic' form showing the automatic% v Figure 6 is a sectional elevation onthe line 7 b 6-6 of Figure 4.

The same reference letters in the different views indicate the same or fsimilarparts,

a indicates the passage by which the exhaust or low'presure steam enters the injector; b the automatic valve which controls the entry of such steam'into theinj ector, such valve being carried by a lever c and c 7 by aspringcl and opened by a piston e. latter is acted upon, by I g and past a valve 9 from" losed steam. obtained through a passage-"7 the passage 71; by which auxiliary live steam is ssupplied to the lowpressure steam is not available. Ihe valve '9' is, on a spindle above whichis a being in 'a chamber y' to valve 11, the latter which live steam from the steam chest or t e t amJ rr y pip f th engine upp ying the exhaust steam supply f too [quickly after steam and 2) in thejpipe 7a.

or low pressure 7 l y f t p p tthesteamchest or 7 that is to passage egains access by NVhen there ,is steam in:

b pipe of the engine, say, when exhaust or low pressure available from, he enginefor' the passage a, the valved is closed on its seat and the valve 9 is opened; Steam can h to] the cylinder which opens the valve 7). a ,Supplementary live steam jector bythe passage m.

[In order to prevent thevalve i being closed has been supplied-to the steam engine chest or supply pipe for the purpose of working, the. engine, there isfprovided the delay valve (shown in Figures 1 Such delay valve is passes to the lettered n and is an automatic valve closing by the difierence off ressure at its two sides.

It has an aperture 0 through its seat. which after the admission ber j, ensures when the valve closes,

toithe chamber j only at 'areducedrate, so

that there is an; appreciable period of time or steam to the steam enginefchest orsupply pipesbefore a pressure is accumulated in the chamber 1' sufficient to cause the closing of the valve i, the opening. of the'valve g and the passage of'stc'am to the cylinder containing the piston/e. This delay action, due to the restriction of the rate of flow of steam in the pipeilq towards the chamthat exhaust or low pressure steam shall be available at the valve Z) before such valve is opened. We thereby, prevent the passage of air 1nto theinj ector before ex-' mentary steam can be regulated by the haust or low pressure steam is available."

The

injector when exhaust or steam to the steam is 7 then {pass from contain ng the p ston e 7 permits steam to pass the injector greater than in the passage a. When the supply of steam to the engine steam chest is discontinued, any return flow from the chamber through the valve n is closes on its seat when there is a pressure in .The control of the auxiliary andlive steam is efiected by the valve shown in 4:, and 6, in which a valve stem 9" is supplies Flgures connected positively to the valve 8 which can trolsthe auxiliary live steam supply to the pipe or passage h, and to a valve t which controls the passage ofsupplementary live steam to the passage m, by a connection which allows a certain amount of free movement of the spindle before the valve t is opened, It will be seen that the valve spindle has a collar u thereon which works in a chamber formed inthefback of the valve, such chamber permitting asbeforedescribed, relative movement of spindle and'valve. I 1 v The valve .10 is-an automatic valve which closes on itsv seat when there is a pressure'in the, in ector greater than in the passage a.

When the supply ofsteam to-theengine steam chest is discontinued, any return flow from the chamber j thro'ughthe valve nis facilitated by the opening'of such valve sothat thou h there is a restrictionof the flow towards y' there is no restriction of flow away from'j, TA cookie is provided in the delay valve to cutoffthe steam supply to j if the injectoris working permanently from the auxiliary live steam supply. r h

I The control of the auxiliary andlive steam suppliesis efi'ected the valve shown in Figures 4, 5, and 6,'*in which a valvestem 7" is connected-positively to the valve 8 whichcontrols the auxiliary live steam supply to the r pe pa ag n b andto a valve 2? which controls the passageof supplementary live steam V to thepassage m,;by a connection which allows a certainamo'unt of free movement of the spindle before the valve t is opened; It willbe seen that the valve spindle has a collar u thereon which works in a chamber formed in the back of the valve, such cham ber' permitting as before described, relative movement of spindle and valve,

With'this' arrangement the valve operating handle ufc'an'be turned to open the. valve .5- and pass auxiliary live steam to the injector without opening the valve t, buta further movement offithe handle 42 will cause the opening ofthe valve 25 so that both auxiliary andsuppl'emcntary live steam will pass to theinjector, and the quantity of the suppleamount of openingof'the valve 2?. r

It will be understood that the auxiliary supply of live steam which works the injec- 'tor when exhaust or low pressure steam is not available is throttled down to low presiure by means of the nozzle, to of restricted ore. r r

' The injector may be worked either by the exhaust steam from the steam engine of the locomotive, or the like, upon which the injector is fitted, or it may be operated by the low pressure steam obtained from the intermediate receiver or low pressure steam chest of a compound engine.

an auxiliary live steam supply and a valve associated with said last mentioned valve by a lost'motion connection for'controlling a supplementary live steam supplyso that said supplementary live steam supply is only available after said auxiliary live'steam supply has been established.

In testimony whereof we have signed our names to this specification.

RICHARD DAVID METCALFE. JAMES CROXON 'METCALFE.

The construction shown in F igure 3 has been indicated in diagrammatic form for the purpose of including various parts which would otherwise be obscure it such figure had been made a correct sectional View of the injector shown in Figure '1. The details of the injector are omitted.

We wish it to be understood thatwe do not in the present application claim any novelty for the construction of injector shown in Figure 3, but this figure has been included for the purpose of making clear the result achieved by the present invention.

- What we claim is:

1. In an exhaust or low pressure steam injector having an automatic valve opened by steam pressure for allowing of the passage of the exhaust or low pressure steam into the injector, for retarding therate of-flow of live steam the arrangement of a delay valve to the injector control fitting so as to delay the production of full steam pressure in such fitting, such valve allowing the free unretarded return flow of steam from the injector control fitting when the live steam supply is out off.

2. In an exhaust or low pressure steam injector having an automatic valve openedby steam pressure obtained from the valve which controls the supply of auxiliary live steam to the injector when exhaust or low pressure steam is not available, the arrangement of a delay valve in the steam pipe line between the steam chest or supply pipe of v the engine from which the injector derives its exhaust or low pressure steam supply and the valve which supplies steam to open the automatic exhaust steam admission valve, so that the latter valve is not opened for an appreciable period after the supply of steamof live steamto the injector control pressure steam into the in-

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